#include <stdio.h>

int main()
{
    int i=1;
    // switch (整形常量表达式)
    switch (i)
    {
    case 1:
        printf("monday \n");
        int num = 2;
        switch (num) // switch 允许嵌套
        {
        case 1:
            printf("this is 1 \n");
            break;
        case 2:
            printf("this is 2 \n");
            break;
        default:
            break;
        }
        break;
    case 2:
        printf("Saturday \n");
        break;
    
    default:
        printf("error \n");
        break;
    }
    
    return 0;
}